A portable vein viewer apparatus may be battery powered and hand-held to reveal patient vasculature information to aid in venipuncture processes. The apparatus comprises a first laser diode emitting infrared light, and a second laser diode emitting only visible wavelengths, wherein vasculature absorbs a portion of the infrared light causing reflection of a contrasted infrared image. A pair of silicon PIN photodiodes, responsive to the contrasted infrared image, causes transmission of a corresponding signal. The signal is processed through circuitry to amplify, sum, and filter the outputted signals, and with the use of an image processing algorithm, the contrasted image is projected onto the patient's skin surface using the second laser diode. Revealed information may comprise vein location, depth, diameter, and degree of certainty of vein locations. Projection of vein images may be a positive or a negative image. Venipuncture needles may be coated to provide visibility in projected images.
